Machine-switching telephone system



June 1 1926.-

R. L. STOKELY MACHINE SWITCHING TELEPHONE SYSTEM Filed June '7, 1923 hven/or:

Patented June 1, 1926.

' UNITED STATES PATENT OFFICE. I

I. STOKELY, OF FLORAL'BARK, YORK,.ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, NEWYORK, N. Y., A CORPORATION OF NEW YORK.

MACHINE-SWITCHING TELEPHONE SYSTEM.

Application filed June 7, 1923. Serial No. 643,870.

operator is provided with two jacks, one a collect jack, and one a refund jack and an auxiliary cord circuit. By inserting the plug of the cord. into one or the other of the acks depending on which of the collect or refund operations'is tobe'c-arriedout, and then operating a dial individual to the cord] circuit, a coin control-switch automatically engages the trunk employed. in establishing the toll connection, and sends over the connection current, characteristic ofthe: jackcmployed, effect. the operationof the coin box mechanism at the subscribers station.

It is an object of this invention to improve the system disclosed in the aforementioned copending application for effecting coin collect and refund operations.

This object is accomplished by providing a system wherein one jack is employed in connection with a pair of manually operable keys for accomplishing the collect and refund operation of the coin box mechanism,

one key being actuated to effect the collection of coins and the other key to effect the refund of coins. Actuation of one keyjinitiates the application of the refund and/am,

tuation of the other key initiates the appli-,

cation of the collect current. The selected.

current is then held connected to the called line independently of the depressed key .until the coin in the coin box is disposed of.

The invention will be readily understood from the following detailed description made with reference to theaccompanying drawing in which a toll train, shown schematically, is adapted to connect a toll operators position at D with a subscribers line of the coin box type represented at A. The schematic representation of the toll train shows a toll operators cord B, a plurality of automatic selectors C. and E, and the connector F. A complete description of the operation of the equipment shown schematically in the ,drawing may be hadby referring to the above mentioned copending ap-' plication, and as this equipment does not enter into the presentinvention, no detailed 6 description thereof will be entered into in this application. Below the trainof automatic switches is shown the circuit details of a coin control switch terminating in a plurality of multiple jacks. To the extreme left an operators cord circuit and dialing equipment are shown, by virtue of which the coin control switch is caused. to aut0- matically engage a trunk line and control the-operation of the coin box mechanism at a distant .subscribers'station, i t

It will be assumed that the toll operator has. established the desired connection over the selectors G and E and connector F and has requested the subscriber at I A to deposit the required amount in coins in the coin receptacle located at station A. I I

Asuming that: the coins have been deposited by the subscriber at A and the operator. at D, having received the tone signals verifying the amountdeposited, desires to collect the same, she picks upthe plug 10 and inserts it into jaclr 11 after noting whether the busy signal 14 is operated or not. The insertion of plug 10 into jack 11 closes a circuit for relays 12 and 13, which may be traced from grounded battery,

tacts of plug 10 and jack 11, to ground,

through the winding of relay 13. Relay 13 operates in this circuit and in attracting its right hand armature effects the-actuation of the drop signals'l l and 15 .located'at the positions at which multiples of jack 11, ap-

pear, to notify the operators thereat that .throughthe winding-of relay 12, sleeve con-i 21, left hand armature and back contact of relay 22, front contact and left hand armature of relay 12, tip contacts of plug 10 and jack 11, conductor 23, winding of relay 20, conductorsi6 and 2 1, outermost right hand armature andback contact of relay 25, outer right hand armature and back contact of relay v26, outer right hand armature and] back contact of relay 2?, conductor 28, ring contacts of jack 11 and plug 10, ring conductor 29 of the cord, normal lower contacts of the dial 230, back contact and right handarmatu-re of relay front contact and ar mature of relay 16, normal contacts of key 17 to ground over the right hand armature and front contact of relay 12. Relay 20 operating in this circuit establishes an obvious circuit for relay 31 the purpose of which will hereinafter appear.

The operator knowing the number or the trunk G employed in establishing the connection to the subscribers line A rotates the dial 230 to send out impulses corresponding to the number of this trunk in order'to' place the coin control switch in operative relation therewith. The apparatus shown at the right of the broken line in the drawing is located at the distant automatic office, that is to say, in the same cities as the selector C. T he equipment at the left of the'broken line is located at the tollol'lice.

Upon the return movement of the dial impulses are transmitted to the impulse relay 20' over the circuit hereinbetoretraced. Upon each retraction-0t the armature of t'his relay an impulse is transmitted over the following circuit tothe vertical magnet of the switch: from ground, armature and back contact oi relay 20, inner armature and front contact of relay 31, normally closed cont-acts of oft-normal switch 33, winding'of slow-torelease relay 3%, to grounded battery, through the winding of vertical magnet 32. As relay 2O follows the interruptions at the dial contacts, the vertical magnet operates in series with relay 3% and raises the switch shaft and its associated wipers to the desired level in the well known manner. Relay 34 being slow-to-release does not tol low the interruption but remains energized between pulses.

Upon the first vertical step of the switchshatt the oil-normal switch operates, so

that the succeeding pulses pass by way of the contact and the armature and front contact of relay 34. the impulses slow relay 5-l releases and prepares a circuit for the rotary magnet 36. lVhen the dial is again actuated to send out the next series of impulses, the pulses traverse a path extending from ground, armature and back contact of relay 20, inner right hand armature and front contact of relay 3]., contact 35 of oft-normal switch armature and back contact of relay 34, conductor 38, winding. of slow release relay 37, contacts 3901? oil-normal switch 4st). to grounded battery, through the winding of rotary magnet 36. Rotary magnet 36 in following the impulses, moves the shaft and wipers around into engagement with the trunk terminals a l and 4-2. Relay 37 operates in series with the magnet 36 but being slow-to-release does Upon the cessation of not follow the impulses. In operating on the first impulse, relay 3'? substitutes its inner armature and front contact tor the lower contactso'l' oil-normal switch it) so that when switch 40 operates on the first rotary step of the switch shaft the pulsing circuit maintained intact.

After the last impulse of this series, re-

lay 37 drops back and closes the following circuit for relay 27. Grounded battery, winding of magnet 36, upper contacts o'l ottn'ormal switch 40, back contact and outer armature of relay 37, conductor ti-5, innermost left hand arn'lature and back contact of relay 25, to ground through the right hand winding of relay 2?. Relay 2'? operates inthis circuit but magnet 36 remains inert, since it is marginal. in attracting its outer right hand armature, relay 2'? removes the normally existing short circuit tron'i the lower windingof relay 4st and the winding of relay This circuit 11121 be traced from the right hand lower winding terminal of relay 4.4, winding of relay 4-5, conductors 46 and Q-Lt, outermostright hand armature and back contact of relay 25, outer right hand armature and back Contact of relay 2G, outer right hand arn'iature and back contact of relay 27, conductor 28, to the left hand lower winding terminal of relay n. The re moval of this short circuit causes relay 415 to energize inseries with relays 20 and ii orer the'tip and ring contacts of jackll and plug 12 tobattery and ground in the cord circuit. Relay it does not operate at this time since the direction of the [low current therethrouglr is not in the proper direction. In attracting its outer left hand armature. relay 27 also establishes a circuit for the upper finding of relay al which may be traced, from grounded battery, upper winding of relay etl, re t ance element (ll, con ductor 50, outer le hand armature and front contact of relay 2?, conductors il and 52, to ground over the outer armature and front contact of relay 3'1. Relay ll is so wound that when both of its windings are energized in opposite directions it does not operate, as in the case just described. Relay 27 in attracting its inner lett hand armature prepares an energizing circuit for its own left hand winding and in attracting its inner right hand armature prepares an energizing circuit for relay 26.

' rlssuming now that the operator desires to collect the coins deposited by the subscriber she actuates key 30 thereby establishing an obvious circuit tor relay 2?. Relay 22 thereupon operates and transposes the tip and ring conductors on the cord thereby causing a reversal of current in the lower winding of relay 4A.

The currents in the windings of relay ll are now in such directions as to 'd each other and relay -l-l accordingly operates, and

llU

in. attracting its lower. armature short-cir cuits resistance 61 in series with the upper winding ofrelay 44 thereby increasing the pull exerted on the armatures of this relay." In attracting its inner lower armature "relay 44'short circuits relay 2O whereupon it re-: leases. control of relays 25,27 and 31 and independently of key 60, so that as soon as the op-' erator depresses the key-60it may be released and the consequent reversal ofbattery flow over the line will not release relay 44. Relay 20 in retracting its armature opens the circuit for slow relay 31, which,

however, is still held operated from ground on the armature of relay 45. A circuitfor relay 26 may now be traced from vgrounded battery, right hand winding of relay 26, normally made contacts of relay 26 left hand winding of relay 26, inner right hand armature and front contact of relay 27, front contact and inner armature ofrelay 31, to ground, over the back contact and armature of relay 20. Relay 26, in attracting its outer right hand armature, opens at another point the short circuit normally existing about the winding of relay 45 and the lower winding of relay 44. In attracting its inner right hand armature relay 26 looks itself to ground at the outer armature of relay 31 by way of the left hand armature, and back contact of relay 71; In attracting its inner left hand armature relay 26 completes a holding circuit for the left hand winding of relay 27 over conductor 86 to ground at interrupter 85. In attracting its outer left hand armature'a circult isestablished for the left hand winding of relay 25 which may be tracedfronrgrounded battery, left hand winding of relay 25, outer left hand armature and front contact of re lay 26, conductor 51, tofground over the outer-armature and front contact of relay 31.

Relay-25 in operating in the circuit previouslytraced, establishes a locking circuit for itself which may be traced from grounded battery, right hand winding of relay 25, front contact and innermost right hand armature of relay 25, conductor 72, front contact and inner armature of relay 31, to ground at the armature and back contact of relay 20. The purpose I of the aforementioned locking circuit for relay 25 is to insure the operation of this relay during the period of collecting the coins at the paystation regardless of whether the operatorhas restored her collect coin key to normal or not. In other words relay 25 is under the joint control of the operators coin key-and the coins in the coin-box. In attracting its innermost lefthand armature relay 25 opens the circuit for the right hand winding of relay 27. The operation of the outermost right hand armature of this relay performs a similar function as does the outer right Relay 44 in operating locksunder hand armatureof relay 26 as hereinbefore of the middle left hand armature of relay 25. This circuit may be traced from grounded battery, upper winding of relay 44, front, Contact and lower armature'ot' relay'44, conductors 50 and 73, front contact and middle left hand armature of relay 25, 'to' ground over the outer armature and front contact of relay 31. Inattractingits outermost left hand armature, relay 25 connects the collect tone signal source 74 to the operators headset (not shown) over the wiper 42, and its associated brush in order to give the. op erator an audible signal during the collectionof coins at the paystation. The condenser 75 in thetone circuit prevents any direct current from the tone apparatus from interfering with the talking circuit of the established connection. lvhen relay 25 operat-ed as hereinbefore described, the circuit forthe right hand winding of relay 27- is opened at the innermost lefthand armature and back contact of relay 25 and should lead 8 6 be associated with an insulating segment of theinterrupter relay- 27 restores; Relay 27 in' restoringopensits locking circuit and establishes a circuit for relay Hover the inner left hand armature and front contact of relay 26, to ground at the interrupter 85. It will be noted that should relay-25 oper ate at a time when thebrush of interrupter 85 is on an insulating segment relay '27 will restore since the circuit for its left hand windingwill also be opened. If, however, relay 25 should open the right hand circuit of relay 27 when the brush is on a metallic segment relay 27 will remain locked up to ground at the interrupter 85 and will remain so operated until the brush makes contact with the next'insulating segment of the interrupter. Relay 27 is locked up to the round on interrupter 85 in order to prevent I it restoring during the period when the inlay 71 for only partof the time during which the lead 86 is grounded. Relay 71 must be operated during the entire period of the grounding of lead 86 so that current of positive polarity frombattery 80 will. be on the line for a sufiicient length of time to insure the proper functioning of the appara tus at the paystation. I K

' Relay 71 operates and at its left hand armature and back contact opensthe lockingcircuit for relay 26, and in attracting its right hand armature places the positive polarity of battery 80 onlthe contact, 42 of the trunk multiple by way of the winding of relay '81. A path now exists whichmay be traced from the positive pole of grounded front contact and right hand armature of relay 71, switch contacts 42,. brush 99,.terminal 98, winding of relay 97,. contacts 92 of relay 93 to ground. Relay 97 operates and connects relay 93 to the interrupter 9t whereupon the coin box mechanism at station- A is operated as completely described in the aforementioned copending application. Relay 81 operates in series with the coin collect and refund apparatus at station A and closes the locking circuit for slow relay 26 which was opened when relay 71 operated. Relay 26, being slow-torclease, however, did not restore during the period existing between the operations of relays 71 and 81. When the ground is removed from the interrupter lead 86, relay 71 restores removing the positive polarity of battery 80 from the line and opening the circuit for relay 81.

If, on the first application of ground to the lead 86 by the interrupter 85, the coin box mechanism did not dispose of the coin, relay 71 on operating when the interrupter ground lead 86 is again grounded performs the functions as previously described. This cycle of operation will be repeated until the coin collect and refund apparatus at station A has disposed of the coinhen the coin collect and refund apparatus at station A has disposed of the coins, relay 71 on operating. when the interrupter ground lead 86 is again grounded opens the locking circuit for relay 26 and associates battery 80 with the contact- 42, through the winding of relay 81.. Sincethe coins have been disposed of at the paysta-tion. A the circuit for the coin collect and refund apparatus is opened at the coin contacts 96 and the circuit for relay 81 will therefore be opened. Relay 26 restores when its circuit is opened by the operation of relay T1 the circuit of relay 81 being opened at the coin contacts 96. The" restoration. of relay 26 does not deen'ergize relay 25' since this relay remains locked from ground at relay 20, over conductor T2 and its own innermost right hand arn'iature and front contact. Re lay 26 in restoring, however, opens at its inner left hand armature and front contact, the circuit for relay 71 which thereupon releases and removes battery from the switch contact 42.

The operator holds key 60 operated until she can recognize the tone signal on the line thereby checking. the operation of the coin collect switch. Upon receiving, this tone, the operator restores her key 60 to normal thereby opening the circuit for relay 22 which restores and reverses the cur rent in the line. Relay will thereupon operate and relay 4-5 will release due tothe reversal of battery in the line circuit. Relay 20 in attracting its armature opens the locking circuit for relay and cloi'es through a holding ground for relay 31. Relay 25 restores and in retracting its outermost left hand armature removes the collect tone from the line. At its middle lefthand armature relay 25 opens up the circuit including the upper winding of relay -Il-l which relay thereupon restores. At its innermost left hand armature relay 25 establishes an energizing circuit for relay 2'? which performs no function at this time since the circuit for relay 71 has already been opened at the inner left hand armature and front contact of relay 26.

It is apparent now that with the same setting of the coin control switch, the operator can again effect the operation of the coin box mechanism in whatever manner she desires either to collect or refund coins.

Should the operator desire to refund the coins instead of collect them as hereinbefore described she will operate the refund key 17 thereby deenergizing slow-to-release relay 16. Due to relay 16 being slow-to-release the circuit for relaysQO and is momentarily opened causing them to release. The operation of marginal relay 20 when the normal contacts of relay 16 are closed is prevented by the inclusion of resistance 70 in its circuit. Relay 15 being sensitive ope-rateshowever. Relay 20 having been energized upon insertion of plug 10 into jack 11 as herein before described. Since key is in its normal position, relay 22 will not energize thereby preventing the reversal of current through the'lower winding of relay l i. Relay i l accordingly remains inert so that negative current frombattery 90 will be sent over the established connection to the coin box station by way of the armature and front contact of relay 71 which will have operated in the same manner as described in connection with the collect operation. The coin box mechanism will then function to refund the coins. At its uppermost armature and back contact relay 14 connects the source 91 of tone current to the wiper 11 to notify the operator that the switch has operated to refund the coins. After receiving the tone the operator restores key 17 to normal. whereupon relay 20 operates. The operation of the remaining apparatus is the same as described in the previous description and need not be repeated.

hen the coins have been properly disposed of, the operator removes plug 10 from jack 11 whereupon relays 20 and 45 restore causing the release of relay 31. A circuit now exists which may be traced from grounded battery through the winding of release magnet 92,.upper contacts of off-normal switch 33, back contact and inner armature of relay 31, to" ground over the back contact and armature of relay 20. The release magnet 92 operates and releases the coin control switch. As the switch shaft restores to normal the upper contacts of oif-normalswitch 40 are opened thereby opening the circuit for the right hand windin of relay 27 allowing this relay to restore. s soon as the shaft restores to normal the circuit for'release magnet 92 is opened "at the upper contacts of the oilnormal switch 33'. c -What is claimed is: i

- 1. In a telephone system, the combination with a telephone line, a connection comprising a connecting circuit, said line and auto-V matic switches, of a coin box at theSubstation of said line having a coin disposal magnet, an operators position, an automatic switch at said position and controlled therer from to connect with said connecting circuit,

an electrical path to saidautomatic switch over which it may be set,-and means for se-. lectlilvely operating said magnet over said pat i v 2. In a telephone system, the combination with a telephone line, a connection comprising a connecting circuit,asaid line and automaticswitches, of a coin box at the substation of said line having a coin disposal mag net, an operators position, an automatic switch at said position and controlled therefrom to connect with said connecting circuit, a source of refund current, a source of collect current, an electrical path to said automatic switch over which it may be set, and

means effective over saidpathfor selecting one of'said currentsources to correspondingly operate said magnet when the connectingcircuit is selected. V l

3. In a telephone system, the combination with a telephone line, a connection comprising a connecting circuit, said line and automatic switches, of a coin box at the substation. of said line having a coin disposal magnet, an operatorsposition, an automatic switch at said position andcontrolled therefrom to connect with said connecting circuit, ajaok in which the circuit leading to said automaticswitch terminates, a source of re- I fund current and a source of collect current,

a dial, a plug adapted to be inserted in said jack to associate said dial with said switch to set the same on said connecting circuit,

and means efiective subsequent to'the insertionof said plug in said jack for selectively associating either of said current sources with said connecting circuit to correspond,

ingly operate said magnet. I

4. In a telephone system, the combination with atelephone line, a connection comprising'a connecting circuit, said line and auto matic switches, of a coin box at the substation of sa'idli'ne having'la coin disposal magnet, an operators position, an automatic switch at said position and controlled therefrom to connect with said connecting circuit, a jack in which the circuit leading to said automatic switch terminates, a source of re fund current and a source of collect current,

current sources with said connecting circuit to correspondingly operate said magnet.

- 5. In a telephone system, the combination with a telephone line, a connection. comprising a connecting circuit, saidline and automatic switches, of a coin box at the substa tion of said line having a coin disposal 1nagnet,an operators position, an automatic switch at said position and controlled therefrom to connect with said connecting circuit, a jack in which the circuit leading to said automatic switch terminates, a source of refund current and a source of collectcurrent, a dial, a plug adapted to be inserted in said jack to associate said dial with said switch to set the same on said connecting circuit, a collect; key, a refund key, and means responsive to the actuation of either of said keys to associate a corresponding source of current with the connectingcircuit I whereby said magnet is operated in a corresponding manner. c c- '6. In a telephone system, the combination with a telephone line, a connectioncomprising a connecting circuit said line and automatic switches, of acoin box at thesubstation of said line having a coin disposal mag net, an operators position, an operators headset thereat, an automatic switch at said position and controlled therefrom to select said connecting circuit, an electrical path connected to said automatic switch over which it may be set, a source of refund cur rent, a source of collect current, means for the combination sis ing a connecting circuit said line and automatic switches, of a coin box at the substaiionof said line having acoin disposal magnet, an operators f position, an operators headset thereat, an automatic switch at said position and controlled therefrom to select said connecting circuit, an electrical path connected to said automatic switchover which it may be -set, a source of refundc'ur rent, a source of collect current, means for selectively associating said current sources with the connecting circuit to operate said magnet in a corresponding manner, two

sources of tone current adapted to be individually associated with said headset in accordance with the character of the current associated with the connecting circuit to operate said magnet, and means ettective incident to the operation of said magnet in removing the tone current.

8. In a telephone system, the combination with a telephone line, a connection comprising a connecting circuit said line and automatic switches, of a coin box at the substation of said line having a coin disposal magnet, an operators position, an operators headset thereat, an automatic switch at said position and controlled therefrom to connect with said connecting circuit,a jack in which the circuit leading to said automatic switch terminates, a source of refund current, a source of collect current, a dial, a plug adapted to be inserted in said jack to associate said dial with said switch to set the same on said connecting circuit, means eitective upon the insertion of said plug into said jack for selectively associating said current sources with said connecting circuit to correspondingly operate said magnet, two sources of tone current adapted to be individually associated with said headset in accordance with the character of the current associated with the connecting circuit, means effective incident to the operation of said magnet in removing the tone current, and. means actuated upon the removal of said plug from said jack for restoring said switch.

9'. In a telephone system, the combination with a telephone line, a connection comprising a plurality of serially connected automatic switches and a subscribers line, a coin box mechanism associated with said line, a coin control switch terminating in a jack at an operators position, a dial, a plug adapted to be inserted in said jack to connect said dial thereto whereby said switch is associated with the serially connected automatic switches, a relay associated with said switch adapted to be energized in such a anner as to remain inert when said plug is associated, with said jack, sources of currents of different characteristics, a second relay, and a key effective in operating said second relay to reverse the current in said first relay and cause it to actuate whereby a. certain one of said current sources is connected to said serially connected switches to operate said coin box mechanism in a predetermined manner,

10., In a telephone system, the combination with telephone lines, a connection comprising a connecting circuit, a pair of said lines automatic switches, of a coin box at the substation of one of said lines having a coin disposal magnet, an operators position, an automatic switch at said position and controlled therefrom to connect with said connecting circuit, a two-conductor circuit extending to said switch over which it may be set, a pair of keys, a source of refund and a source of collect current, means controlled by said keys for selectively applying said refund and said collect current to said coin box, and means for automatically continuing the application of the selected current to the coin box until the coin is disposed of. 1

11. In a telephone system, the combination with telephone lines, a connection comprising a connecting circuit, a pair of lines and automatic switches, of a coin box at the substation of one of said lines having a coin disposal magnet, an operators position, an automatic switch at said position and controlled theret'rom to connect with said connecting circuit, a jack in which the circuit leading to said automatic switch terminates, a source of refund and a source of collect current, a dial, a plug adapted when inserted in said jack to associate said dial with said switch to enable the operator to set the same switch on said connecting circuit, a key for each source of current, and means controlled by said keys for selective-ly impressing current from the corresponding source to cause said coin disposal magnet to collect or refund the coins.

12. In a telephone system, the combination of telephone lines, a connection comprising a connecting. circuit, a pair of said lines and automatic switches, of a coin box at the substation oi one of said lines having a coin disposal magnet, an operators. position, an automatic switch at said position and controlled therefrom to select said connecting circuit, a two-conductor circuit 8X- tending to said switch over which it may beset, a source of refund and a source of col-- lect current, a pair of keys: for selectively applying said sources of refund and collect current to the coin. box, two: sources of tone current the corresponding one of which is connected to said connecting circuit when current is applied tothe line to operate said coin disposal magnet, and means for maintaining the tone source connected to the connecting circuituntil: the coin is disposed of and the selected! key is restored tonormal.

In witness whereof, I hereuntosubscribe my name this 31st day of May A. D., 1923.

RAY L. STDKELY. 

